New research links acute lymphoblastic leukemia (ALL) to a mutation in the Ikaros gene, according to Science Now.
ALL is a rapidly growing cancer of lymphocytes, or white blood cells. In ALL patients, lymphocytes fail to develop properly and ultimately lack the capacity to fight infections. The population of abnormal cells increases quickly and crowd out normal blood cells. ALL is an aggressive cancer that is difficult to treat, the Marrow Donor Program website reports.
ALL patients were found to share a specific “Philadelphia” chromosomal defect with people diagnosed with chronic myelogenous leukemia (CML). CML is a less aggressive leukemia.
CML patients also produce too many white blood cells in their bone marrow. Unlike ALL and other acute leukemias, immature white blood cells are not present in large numbers. Patients with CML are often cured with treatment, the Merck medical manual states.
About 25 to 30 percent of ALL patients have the same Philadelphia chromosomal defect that is closely correlated with CML, leading researchers to question why people develop one form of the leukemia versus the other.
Researchers at St. Jude Children’s Research Hospital in Memphis, Tenn., studied both CML patients and ALL patients, looking for a link between Ikaros and ALL. The study included 21 children and 22 adults who had been diagnosed with ALL and who also had the Philadelphia chromosomal defect. Mutations in the Ikaros gene were found in 76.2 percent of children and 90.9 percent of the adults who were studied. In the group of 23 patients with CML who did not have ALL, mutations in the Ikaros gene were not found. These findings suggest that the Ikaros gene is linked to ALL in patients with the Philadelphia chromosomal abnormality, Science Now said.
While it is not yet understood how the mutation in the Ikaros gene causes ALL, scientists have found that the Ikaros gene regulates lymphocyte development, as reported in Molecular Cell Biology in 1994.
“One possibility is that the faulty protein produced by the mutations leads to abnormal lymphocytes that turn cancerous,” James Downing, who leads the group at St. Jude, told Science Now.
Researchers hope that this link will lead to new treatments for ALL.